I believe the 231 changed in 1990 but only in the cherokees and they lost the tail shaft. My 1989 says amc231 on the tag but I have a 1990 transfer case that says np231J and doesn't have a tailshaft so I can only use the chain and internals, thats why I asked where to find the tailshaft.

So i followed the post (great job btw) and replaced my seal after finding a leak at the output. I actually found the leak because items i left on the floor behind the seats kept getting damp and i could not figuer out why. Looked underneath and saw that the oil was being splattered up on the underside during rotation. Thought it might be coming up through the seatbelt hold down bolt.

I replaced the seal and u-bolts and put new silicone/tightened the bolts on the extension. I did not put a new bushing in however

After that i put about 200miles on the jeep and am now noticing that some of the silicone has fallen out between the extension cone and the housing, and the output seal seems to have backed out a bit (not all the way just a little on the bottom). I am still getting some leaking although i am not sure from where as the drive-shaft is pretty clean near the seal still. Should i look to repeat the process and get a new bushing or am i looking for something bigger that may be causing enough vibration/movment to explain this? Any ideas are appreciated.

I am experiencing a slow drip right out of the seal itself... somone suggested that the output shaft itself may be very slightly worn from the seal if its the original from 93 (which I think it is...) and there is now just enough space for a slow seapage... I am not sure if this is possible but can tell you there is no real "play" in the shaft... although I guess I am not sure what type of play there should be and when its too much. I am happy to say that I tourqued everything up and nothing has backed out - the output shaft extension(tail cone) is dry as a bone...

Not really sure what 'play' there should be. I know there was alot of movement in the u-joints so i replaced them. kinda thought maybe that was the culprit but nope. shaft seems dry, and cone too. but i see a slow leak and freddy kruger type splatters all over the underside so not sure what to make of it. I guess at the minimum im going to have to clean everything up really nice and try to find it early. before everything starts looking like a murder scene again and yep, mine is the original from 89...

Sentinal02, thank you so much for this post; amazing I was just outside doing the exact same thing, but with a new housing...and I am glad I saw you post because I thought I was missing something. (Just an FYI your links to the pics are broken).

Here is a picture similar to mine, the type with a rubber boot and I have replaced this seal two times. It leaks more than before. The first time the "C" clip just in front of the seal tore the seal. I am still working on the second time. Does anyone have any suggestions or experience with this this seal.

D, can't really help you much with that myself since the TJ's housing is a bit different obviously. I've only done an SYE on one, never messed with the stock output seal. hopefully one of the other guys can help you out.

I found the answer to my TJ rear seal leak issue. The problem has to do with my install. In my previous post I linked to a picture of the TJ seal, retainer clip and slinger. The retainer clip goes into a groove on the shaft, this groove has been the problem. I went Nogalitoes Gear in San Antonio, the guys there tell me to put some tape on the shaft to cover the groove as I am installing the seal. This will let the rubber portion of the seal glide over the groove, where in the past I had allowed the seal to fall into the groove as I was installing. I felt a little springy action as I was driving seal home, this springy feel was my seal tearing past the groove.

The tape is to be removed once the seal is installed. There is also a $100 special tool that will accomplish this task. I'll stick to the tape.

If the bushing is bad and there is a little bit of play in the slip yoke, can it vibrate similar to a bad u-joint? I have a brand new driveshaft, and the driveline angles are OK, but it vibrates terribly.

my bushing seems to fit tight when installed but after driving it for a while, it always seems to come loose and seperate from the rear extention housing where i installed it... is there any ways to prevent this..

my bushing seems to fit tight when installed but after driving it for a while, it always seems to come loose and seperate from the rear extention housing where i installed it... is there any ways to prevent this..

Your bushing or your seal??? The bushing is internal and should be really tight. The seal, if its correctly, and installed all the way in should not move at all.